Abstract
Introduction
The use of Digital Radiography (DR) offers many advantages in the clinical department however each manufacturer has their own unique Exposure Index (EI) value. Confusion can occur among radiographers working across several DR manufacturers in the one department. The International Electrotechnical Commission (IEC) 62494-1 standard published in 2008 sought to simplify EI using three terms for use with all DR manufacturers. This investigation examines if IEC 62494-1 provides a reliable visual indicator to the radiographer that the patient is appropriately exposed and within national Dose Reference Levels.
Methods
EI calibration method and Target EI values were sought from three manufacturers. A clinical study of 30 examinations per room for five body parts (n=1200) was performed. Retake analysis was carried out over a three month period. Experimental studies were undertaken with the aid of Medical Physics to determine if EI was calibrated. Where suboptimal calibration was found, corrective measures were put in place. A second clinical study and retake analysis was undertaken to determine any improvements in image quality.
Results
On initial inspection, only the Carestream equipment was found to be compliant with IEC 62494-1. Siemens and Shimadzu/Canon hybrid systems required corrective measures as a correlation between deviation index and dose was not evident. Retake analysis demonstrated less than 1% of examinations were due to exposure factors and the majority were due to radiographer technique. Dose audits revealed image optimisation was required in several organ programs.
Conclusions
Radiography departments need to programme their own organ-specific EITs in conjunction with the doses received. Greater knowledge of image optimisation in DR is paramount to ensure continued adherence to ALARA.
The use of Digital Radiography (DR) offers many advantages in the clinical department however each manufacturer has their own unique Exposure Index (EI) value. Confusion can occur among radiographers working across several DR manufacturers in the one department. The International Electrotechnical Commission (IEC) 62494-1 standard published in 2008 sought to simplify EI using three terms for use with all DR manufacturers. This investigation examines if IEC 62494-1 provides a reliable visual indicator to the radiographer that the patient is appropriately exposed and within national Dose Reference Levels.
Methods
EI calibration method and Target EI values were sought from three manufacturers. A clinical study of 30 examinations per room for five body parts (n=1200) was performed. Retake analysis was carried out over a three month period. Experimental studies were undertaken with the aid of Medical Physics to determine if EI was calibrated. Where suboptimal calibration was found, corrective measures were put in place. A second clinical study and retake analysis was undertaken to determine any improvements in image quality.
Results
On initial inspection, only the Carestream equipment was found to be compliant with IEC 62494-1. Siemens and Shimadzu/Canon hybrid systems required corrective measures as a correlation between deviation index and dose was not evident. Retake analysis demonstrated less than 1% of examinations were due to exposure factors and the majority were due to radiographer technique. Dose audits revealed image optimisation was required in several organ programs.
Conclusions
Radiography departments need to programme their own organ-specific EITs in conjunction with the doses received. Greater knowledge of image optimisation in DR is paramount to ensure continued adherence to ALARA.
| Original language | English |
|---|---|
| Pages | 1 |
| Number of pages | 1 |
| Publication status | Published (in print/issue) - 27 Feb 2019 |
| Event | European Society of Radiology - Austria Duration: 27 Feb 2019 → 3 Mar 2019 https://ecronline.myesr.org/ecr2019/index.php?p= |
Conference
| Conference | European Society of Radiology |
|---|---|
| City | Austria |
| Period | 27/02/19 → 3/03/19 |
| Internet address |
Keywords
- Exposure
- EI value
- digital radiography
